Magnetic typewriter



y 23, 1961 J. E. HICKERSON 2,985,135

MAGNETIC TYPEWRITER Filed May 28, 1959 5 Sheets-Sheet l JOHN E. HICKERSON ATTORNEY.

FIG.1

May 23, 1961 J. E. HICKERSON 2,985,135 MAGNETIC TYPEWRITER Filed May 28, 1959 5 Sheets-Sheet 2 FIG. 2

y 1961 J. E. HICKERSON 2,985,135

MAGNETIC TYPEIWRITER Filed May 28, 1959 5 Sheets-Sheet 3 May 23, 1961 J. E. HICKERSON MAGNETIC TYPEWRITER 5 Sheets-Sheet 4 Filed May 28, 1959 FIG. 6

FIG. 5

y 1961 J. E. HICKERSON 2,985,135

MAGNETIC TYPEWRITER Filed May 28, 1959 5 Sheets-Sheet 5 H 9 TAB E V o I2 1 T 35 jl P H LRZb ELl Mb 186 I T PRINT CLUTCH MAGNET SPACE BAR mui'u b Twas 106 105 a? 130 PT U INKING SOLENOID ESC. MAGNET 12? R1411 lg I fi jT fil 128 R1 If 1 I FIGQIO o A A 7 CURRENT TRANSFORMER 1 United States Patent MAGNETIC TYPEWRITER John E. Hickerson, Lexington, Ky., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Filed May 28, 1959, Ser. No. 816,466

14 Claims. (Cl. 118-11) This invention relates to typewritersyand more particularly to typewriters which operate on the actuation of type keys to write characters magnetically on a tape, the characters then being developed by powdered ink and printed on a sheet of paper.

There are in conventional typewriters a number of objectionable features which would not exist in a machine operating to write characters magnetically on tape and then developing the characters with powdered ink and printing them on a sheet of paper. In the first place, the striking of type bars against a platen in the conventional machine produces objectionable noise. By writing characters magnetically on a tape and then pressing it against a sheet of paper after the characters have been developed with powdered ink, printing may be obtained with substantially no noise.

Since information is printed directly on a sheet of paper in the conventional machine, there is always a problem when a mistake is made. The operator must either erase the incorrect character and try again to type the correct character in the same spot or type again the entire sheet. When the information is written first on a tape, the operator can make sure that it is correct before transferring to a sheet of paper. The conventional typewriter also requires an inked ribbon which must sooner or later be replaced. This is always an inconvenience since it requires time and usually gets the hands soiled. In a machine of the type proposed, an endless magnetic tape is employed. This may be used indefinitely without changing, and ink in powder form adheres to the tape only on the surface which has been magnetized in the shape of various characters. Any ink left on the tape during a printing operation is removed later as the tape passes an erase head. Printing in upper or lower case may be accomplished by merely timing the pulsing of a head which writes information magnetically on the tape.

An object of this invention is to provide an improved typewriter.

Another object is to provide a typewriter which operates on the actuation of a type key to write on a magnetic tape the character corresponding to the key actuated, the character then being developed with powdered ink and, after writing one line of information, moved against a sheet of paper for printing the complete line.

Another object is to provide in a machine which writes information on a magnetic tape, improved means by which the operator is able to see what has been written and what position on a sheet of paper the information will be printed when a print key is actuated.

Still another object is to provide an improved device for applying to a magnetic tape at each print position a measured quantity of powdered ink after characters have been impressed magnetically on the tape by a write head.

Yet another object is to provide in a typewriter having a magnetic tape on which characters are written, means operating on the actuation of a tabulation key to advance the tape until the first character in the written line is at a predetermined point with respect to the left edge of the paper.

Another object is to provide means which operate automatically, after writing a line of information of predetermined length on a magnetic tape, to advance the tape to a position for printing while at the same time disabling mechanism by which information is written on the tape.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a perspective view of a typewriter in which the present invention is embodied,

Fig. 2 is an enlarged perspective view showing a section of tape having recorded upon it information which is reflected by a mirror.

Fig. 3 is an enlarged sectional view of the type wheel and the magnetic head associated therewith.

Fig. 4 shows enlarged portions of disw forming the type wheel.

Fig. 5 is an enlarged sectional view of a device for delivering a metered quantity of powdered ink to the magnetic tape.

Fig. 6 is an exploded view of the device shown in Fig. 5.

Fig, 7 is an exploded view of a mechanism for turning the tape to a vertical position during a printing operation.

Fig. 8 is a vertical sectional view showing pressure bars and means for moving them to press the tape and paper together during printing.

Fig. 9 is a diagram showing the wiring between various function keys and control mechanisms.

Fig. 10 is a circuit diagram for an electrical heating unit in one of the pressure bars.

Referring to Fig. 1, it will be noted that there is shown a typewriter having type keys 1 which may be actuated manually for writing alphabetic, numeric, or special characters magnetically on a tape 2. A type wheel 3 has inserts 4 on which the various characters are embossed at one end, and the tape 2 lies closely adjacent the path in which these ends travel when the wheel is rotated. Cooperating with the type wheel is a magnetic head 5 which operates when energized to pass magnetic flux through one of the inserts and the tape 2 for magnetizing the latter over an area shaped like the character on the insert. When a key 1 is actuated, a circuit is established for energizing the head 5 at the instant the insert carrying the character corresponding to the actuated key comes under the head 5. The tape is then advanced past a device 6 which blows a metered quantity of ink in the form of magnetic powder over the tape 2, This ink adheres to the tape only on the magnetized area, and so the character becomes visible. Characters are so formed on the inserts 4 that they are written on the tape 2 inverted as far as the operator of the machine is concerned. As shown more clearly in Fig. 2, a mirror 8 is supported in an inclined position over the tape so that any information written thereon may be easily read by the operator. This mirror has on its rear side a thin smoke-like film which not only reflects information from the tape but also permits the operator to look through the mirror and see what information is already printed on a sheet of paper 9.

When a line of information has been written on the tape and moved to the proper position relative to the sheet of paper by actuation of a tab key 12 or by automatic operation of other mechanism to be described later, a print key 14 may be actuated to effect a twisting of the tape portion carrying information to a vertical position so it may be forced against the paper by pressure bars and 16 to cause printing. information is printed on the paper in alignment with the image which appeared on the mirror before printing. Because of this, the operator can see before printing if the new line will be located properly both vertically and horizontally relative to information already printed. The tape 2 forms a continuous loop and passes over a driven pulley 17 and idler pulleys 18, 19 and 29. Any ink remaining on the tape after a printing operation is removed later by an erase magnet 22 and by brushes "23.

For driving the various mechanisms there is'provided, as shown in Fig. l, a motor 24 which operates continuously through bevel gears 25 to drive a shaft 26. Fixed to this shaft is a bevel gear 27 for driving gearing 29 to rotate the brushes 23. At the right hand end of the shaft 26 is a bevel gear 3% meshing with a bevel gear fixed to a vertical shaft 32. The type wheel 3 is fixed to the upper end of the shaft 32 and is driven with the latter continuously at a high speed in a counter-clockwise direction to move the inserts 4 serially past the Write head 5.

As shown in Figs. 3 and 4, the type wheel 3 comprises a pair of circular plates 35 and 36 made of a non-magnetic material and arranged on the shaft with a slight clearance 37 between them. Extending through the plates adjacent their peripheries are openings in alignment with each other and adapted to receive the inserts 4 which are made of magnetic material. The adjacent ends of each pair of aligned inserts are shaped to present one of the characters in embossed form. Characters on the upper inserts, as shown in Fig. 4, are in their true form while those on the lower inserts are in a mirror image form. The arrangement of the inserts within the openings is such that the lower edges of the characters are adjacent the outer periphery of the type wheel, and the characters on the upper and lower plates are in direct alignment with each other. Tape 2 extends through the clearance 37 between the plates at the rear edges of the latter as shown in Fig. 3. It will be seen that a passing of magnetic flux through a pair of aligned inserts will cause the flux to pass through the tape while concentrated in the shape of the character embossed on the inserts. As a result of this, the character is magnetically written on the tape. The writing of some characters, such as M, require a greater amount of flux than others, such as I. To regulate the amount of flux passing through the character inserts, there are provided by-pass inserts 39 which are varied in cross sectional area in inverse proportion to the size of the character to be written. Pole pieces 4% and 41 on the write head extend over the ends of the inserts 4, 3?, and a winding 42 on the head produces when energized a magnetic flux in excess of that required for writing any character. Flux needed for magnetizing the tape in the shape of the character is passed through the inserts 4, and the excess flux is passed through the inserts 39. The number of inserts 4 is such that there is one for each of the upper and lower case characters including alphabetic, numeric and special characters. All of those assigned to lower case are arranged around one half of the print wheel, while those assigned to upper case are arranged around the other half. The reason for this will be made clear later. The upper case character for each key is carried by an insert diametrically opposite the insert carrying the lower case character for the same key.

Mounted on the shaft 32 is a gear 45 meshing with a gear 46 which is fixed to a shaft 47 carrying a contact arm 48. A stationary disc 45% is arranged adjacent the arm 48 and carries a number of contacts 50 which may be connected serially by the arm 48 to a ring 52 mounted on the disc. The contacts 50 are equal in number to the characters which may be printed by either half of the type wheel .3. The arm 48 moves over the contacts 50 in synchroniszn with the movement of the character inserts 4 past the write head 5. One of the contacts 50 is connected to the ring 52 each time one of the character inserts comes under the write head 5. Since there are only half as many contacts 51 as there are inserts assuming that each key 1 may be actuated to type either an upper or lower case character, then the ratio between the gears 45, 46 must be such as to drive the arm 48 two revolutions for each revolution of the type wheel 3.

Spaced along the shaft 32 are two stationary discs 54 and 55. Mounted on disc 54 are two contact segments 56 and 57, each extending approximately 180 around the disc adjacent its periphery. A contact arm 59 is fixed to the shaft 32 and is adapted to connect the segments 56, 57 serially to a ring 60 on the disc. The two se ments are connected to the positive side of a voltage supply at 61, and the ring 60 is connected through a conductor 62, normally open contacts Rib of a relay R-l, and the hold winding of relay R4 to the negative side of the voltage supply.

Mounted on the disc 55 are two contacts 64, 65 arranged approximately 180 from each other and at points underlying the ends of the segments 56, 57which are first engaged by the arm 59 as it rotates. An arm 66 is connected to the shaft 32 and operates to connect the contacts 64, 65 to a ring 68 mounted on the disc 55 and connected by a conductor 6? through normally closed relay contacts R2a and the pick winding of relay R-l to the negative side of the voltage supply. The contacts 64, G5 are connected through conductors 70 and 71, respectively, to contacts 72, 73 which may be connected selectively by a transfer contact 74 through contacts 75 (normally open) and a condenser 76 to the negative side of a voltage supply. Transfer contact 74 is normally in a position to engage contact 72 but may be moved by a shift key 77 to a position engaging contact 73. Arranged under the key lever 1 is a bail 78 which is operated on depression of the key lever to transfer contacts 75. The normally closed side of contacts 75 is connected to the positive side of the voltage supply so the condenser 71? is charged when the key lever is raised. Associated with each key lever 1 is a set of contacts 89 which normally connect a condenser 81 between the positive and negative sides of a voltage supply. This results in a charging of the condenser. When the key 1 is actuated. the contacts are transferred to connect the condenser through a conductor $2 to one of the contacts 50 on the disc 49. As the arm 48 rotates and engages the contact connected to the condenser 81, a connection is made from the conductor 8-2 through the arm 48 and the ring 52 to a conductor 84 leading to one side of relay contacts Rla which are normally open. The other side of the contacts Rla is connected through a resistor 85 to the negative side of the voltage supply, and through a resistor 86 to the grid of a tube 83. The anode of the tube is connected through a resistor 90 to the positive side of the voltage supply, and is also connected through a condenser 91 and the Winding 42 on the Write head 5 to the negative side of the voltage supply.

Assuming that the shift key 77 is in the position shown and the key lever l is depressed, a circuit is completed from the negative side of the voltage supply through the condenser 81, the contacts 80 transferred, and the conductor 32 to one of the contacts 50. Since the key lever is depressed, the bail 78 is rocked to a position trans ferring the contacts 75 to complete a circuit from the negative side of the voltage supply through the condenser '76, contacts 75 (normally open), the contacts 72 (normally closed) and the conductor 70 to the contact 64. When the arm 66 engages the contact 64-, a circuit is completed from this contact through the ring 68, the conductor 69, relay contacts RM and the pick winding of the relay R4 to the negative side of the voltage supply. Simultaneously with the energizingv of this relay by the condenser 76, the arm 59 engages the cont act segment 56 and completes a circuit from the'positive side of the voltage source at 61' through the ring '60, the conductor 62, the contacts Rib (now closed) and the hold winding of relay R1 to the negative side of the voltage supply. This circuit energizes the relay R-l as long as the contact arm 59 engages the segment 56. Since the arm 59 is fixed to shaft 32 which rotates half as fast as the shaft 47, then the contact arm 48 will make one revolution and engage each of the contacts 50 during the time that arm 59 engages segment 56. During this same period, print wheel 3 rotates 180 to move the inserts 4 bearing lower case characters, under the head 5.

As soon as the relay R-l is energized, its contacts Rla close and complete a connection from the ring 52 through conductor 84, the contacts Rla and the resistor 86 to the grid of the tube 88. A connection is also completed from the ring through the contacts R111 and the resistor 85 to the negative side of the voltage supply. When the arm 48 engages the contact 50 which is connected to the contacts 80 of the depressed key lever, a circuit is completed from the condenser 81 through the contacts 80, the conductor 82, the arm 48, the ring 52, conductor 84, contacts Rla and resistor 85 to the negative side of the voltage supply. This results in a discharging of the condenser through the circuit to produce a positive voltage which is applied to the grid for causing the tube 88 to become conductive. The condenser 91 then discharges through a circuit including the tube 88 and the turns 42 on the Write head. At this instant, the insert bearing the character corresponding to that of the depressed key lever is under the head 5 so that magnetic flux produced by the head causes this character to be written on the tape. After the condenser 81 has discharged, the tube 88 becomes non-conductive and the condenser 91 begins charging again through the resistor 90 and the connection to the positive side of the voltage supply. The rate of charging is comparatively slow and is insutlicient to cause a. writing of any character from the type wheel.

If the shift key 77 had been depressed at the time the key lever 1 was actuated, then a connection would have been completed from the negative side of the voltage supply through the condenser 76, the contacts 75 (normally open), the contact 73 and the conductor 71 to the contact 62. Engagement of the contact arm 66 with the contact 65 would have caused relay R1 to be picked up, and this would have been 180 later than it was when operating with the shift key in raised position. The contact arm 59 would then engage segment 57 to maintain the hold circuit for relay R1. During this time, the inserts 4 bearing upper case characters would be passing under the write head 5 so that the completion of a circuit by engagement of the arm 48 with the contact 50 corresponding to the depressed key lever would cause a writing of the upper case character for that lever.

The speed of the shaft 47 is such that the arm 48 sweeps over the contacts 50 approximately three times during a period equal to that during which a key lever is held depressed at normal typing speeds. Each of the contacts 50 will be engaged by the arm at least two or three times for each actuation of a key lever. It makes no difference how many times the active contact 50 is engaged before the key is released because the condenser 81 is discharged the first time it is connected to the circuit including the tube 83 and cannot be recharged until the key lever is raised. Contact arm 48 must rotate at the speed mentioned above because, under the worst condition, the contact arm 66 will have just passed the effective one of the contacts 64, 65 when the key lever 1 is depressed. This means that the arm 66 must then make almost one revolution before the effective contact is engaged to cause an energizing of relay R-1, and the relay contacts Ritz must be closed in order to write a character on the tape. While the arm 66 makes this one revolution, the contact arm 48 makes two revolutions. After the relay contacts Rla are closed, the arm 48 must make at least one revolution while the key lever is depressed since the contact 50 made effective by the key lever may he the one passed over just before the contacts Rla closed. To make the machine operable to write at higher typing speeds, it is only necessary to drive the contact arms at higher speed.

With the actuation of the key lever 1 to write a character on the tape 2, it is essential that the tape be advanced one character space so it will be in a position for receiving another character from the type wheel. As mentioned above, the tape passes over a pulley 17 which may be driven for advancing the tape to the left past the sheet of paper. For driving the pulley, there is provided a belt which is driven by the motor 24 and operates through a friction clutch 96 to drive a shaft 97 on which the pulley 17 is mounted. Fixed to the shaft 97 is a ratchet wheel 99 normally held by a dog 100 to prevent rotation of the shaft. An escapement magnet 101 is operable when pulsed to disengage the dog from the ratchet wheel and permit the latter to rotate one tooth. One side of the magnet 101 is connected to the negative side of the voltage source and the other side is connected through a conductor 103, relay contacts R3a (normally closed), conductor 104, relay contacts Rlc (normally closed), transfer contacts 105 (normally closed), and a condenser 106 to the negative side of the voltage supply. The normally open side of the relay contacts Rlc is connected to the positive side of the voltage supply and is connected through the transfer contacts 105 (normally open) to the condenser 106.

During a writing operation, the contact arm 66 engages either the contact 64 of the contact 65 to complete a circuit for energizing the relay R1. When this takes place, the contacts Rlc transfer and connect the positive side of the voltage supply through the transfer contacts 105 (normally closed) and the condenser 106 to the negative side of the voltage supply. This causes the condenser to be charged. Relay R1 is held energized while the contact arm 59 passes over either the contact segment 56 or the segment 57. When the arm moves off the end of the effective segment, relay R1 is de-energized and its contacts Rlc transfer to normal positions connecting the condenser 106 through the conductor 104, contacts R3a, the conductor 103 and the escape magnet 101 to the negative side of the voltage supply. This causes the condenser to discharge so as to pulse the magnet for lifting the dog 100 and permitting the ratchet wheel to rotate one tooth. Pulley 17 rotates the same amount and feeds the tape one character space.

For advancing the tape to provide a space between words, a space bar 109 is operatively connected to the transfer contacts 105 so as to actuate the latter when the bar is depressed. It will be seen that a depression of the bar causes the contacts 105 to transfer and connect the condenser 106 between the positive and negative sides of the voltage supply. When the space bar is released, contacts 105 assume their normal positions and connect the condenser through the contacts Rlc (normally closed) and the conductor 104 to the escape magnet 101 so as to pulse the latter and cause an advancement of the tape 2.

As the tape advances with the writing of characters thereon, it moves past the device 6 which blows a magnetic powdered ink over the tape for developing the characters. This device comprises, as shown in Figs. 5 and 6, a hopper 112 in which the ink powder is contained. Formed in the hopper between its ends is a slot 113 through which the tape 2 passes. Beneath the hopper is a disc 114 having openings 115 which are moved one at a time into alignment with an opening 116 in the bottom of the hopper. At the lower side of the disc is a valve block 118 having a flat upper surface which is engaged by the disc with a close sliding fit. Formed in the valve block is a passage 119 opening through the upper surface of the block at a point spaced from the opening 116 in the hopper but located in the path of the openings 115 so that ink deposited in the latter will drop into the passage 119 as the disc is rotated. The passage 119 opens into another passage 120 to which air is supplied from a continuously operating compressor not shown. Air flowing through the passage 12% picks up powdered ink dropped into it from the passage 119 and carries the ink to the upper portion of the hopper 112 where it is blown over the surface of the tape 2.

The disc 1 14 is connected to a shaft 122 having a ratchet wheel 123 fixed to its lower end. An arm 124 is loosely mounted on the shaft 122 and carries a dog'126 cooperating with the ratchet wheel to rotate the latter one tooth when the arm is actuated in a clockwise direction in Fig. 6 by a solenoid 127. This solenoid is connected at one end, as shown in Fig. 9, to the negative Side of a voltage source and to one side of a condenser 128. The other end of the solenoid is connected through transfer contacts 130 (normally closed), conductor 131 and relay contacts R1d (normally closed) to the other side of the condenser 128. The normally open sides of the transfer contacts 131) and the relay contacts R10! are connected to the positive side of the voltage source. Contacts 130 are arranged, as shown in Figs. 1 and 9, for actuation by the space bar 109.

When any one of the key levers 1 is depressed to cause the writing of a character on the tape, the relay R1 is energized as described above. This causes the relay contacts Rld to transfer and connect the condenser 128 across the voltage source so it becomes charged. As soon as the character is wnitten on the tape, relay R1 is tie-energized to cause an advance of the tape one character space and, at the same time, to cause a return of the relay contacts Rid to normal position for connecting the condenser 128 directly across the solenoid 127 through the transfer contacts 130 (normally closed). The solenoid is thereby pulsed by the condenser and swings the arm 124 to rotate the disc 114 so as to bring the next opening 115 in alignment with the passage 119. Powdered ink contained within the opening 115 is deposited into the passage 119 and is carried by air through the passage 12%) to the upper side of the tape. 2.

It is possible to write a character on the tape and to locate the inking device so that the character is developed on movement of the tape one character space after writ ing takes place. This makes it necessary that the inserts 4 be located very close to the periphery of the type Wheel, that the tape pass between the discs of the type wheel close to its axis, and that the head 5 be arranged to effect a writing through inserts when they are near the side of the wheel adjacent the device 6. As shown herein, the spacing between the write head 5 and the device 6 is equal to several character spaces. In order to deliver ink to the last characters written in the line, the space bar 109 is operated to step the tape ahead until each portion of the tape bearing a character has come into position to hav powdered ink blown over it. Each operation of the space bar results in a transfer to contacts 130 for connecting the condenser 12S across the voltage supply and causing it to be charged. When the space bar is released, the condenser 128 is connected across the solenoid 127 and energizes the latter to rotate the disc 114 to a position connecting another opening 115 to the passage 119.

When the operator observes from the mirror 8 that all of the information desired for one line of printing has been written on the tape, the tab key 12 may be actuated to cause the tape to move until the first character at the left end of the line is at a predetermined point with respect to the left edge of the paper. This is accomplished by providing contacts 134 which are controlled by the tab key and normally connect a condenser 135 between the positive and negative sides of a voltage source. The contacts 134 are transferred on actuation of the tab key and complete a circuit from the negative side of the voltage source through the condenser 135, the contacts 134 (normally open) and the pick winding of a relay R3 to the negative side of the voltage source. Relay cohtacts R311 transfer and connect the escape magnet 101 through the conductor 103 to the positive side of the voltage source. At the same time, contacts R3b close and complete a circuit from the hold winding of relay R3 through a conductor 136 and contacts 137 to the positive side of a voltage source. The contacts R3a are then held transferred to energize the escape magnet so the shaft 97 may be driven by the belt 95. Fixed to the shaft 97 is a disc 139 having openings 140 (Fig. 9) in which a pin 141 may be selectively inserted. Arranged adjacent disc 139 is an arm 142 which may be actuated by the pin 141 for opening the contacts 137 when the disc has been rotated to a predetermined position. The pin is located to open the contacts when the tape 2 has moved until the left end of the written line is at the desired position. Opening of the contacts 137 results in a breaking of the circuit through the hold winding of the relay R3. Contacts R3a then move to their normal position and cause the escape magnet to be de-energized.

Means are provided to prevent the writing of characters and the advancing of the tape in response to actuations of the key levers when the written line on the tape has reached a predetermined maximum length. This means comprises contacts 144 which are closed by a pin 145 in a second row of openings 146 in the disk 139' when the disk has rotated a predetermined angular distance. The closing of the contacts completes a circuit through a conductor 147 and the pick winding of relay R2 to cause its contacts RM to open and its contacts R212 to close. A circuit is completed by contacts R2b through the hold winding of relay R2 and the contacts 137. The opening of contacts R2a prevents the relay R1 from being picked up by actuation of a key lever 1, and without this relay picking up, no energizing of the head 5 or the escape magnet 101 can take place when a key lever is operated. The tab key 12 may then be operated to energize the escape magnet and cause a driving of the tape until the pin 141 opens the contacts 137. This causes the relay R2 to be de-energized, and also causes the relay R3, picked up on depressing the tab key, to be dropped. The written information is now in a position for printing, andthe keys 1 are effective to write further information. With a control of this type, it is essential that the circumference of the pulley 17 be equal either to the length of a written line plus the distance it must move to bring it into position for printing or to a multiple of these distances.

When a line of information on the tape is in position for printing, the print key 14 may be actuated to cause a printing of the information on the paper 9. This causes a tilting of the tape section carrying the written information to a vertical position and then a moving of the pressure bars 15 and 16 against opposite sides of the sheet 9 and tape 2. For tilting the tape, there is provided at a point adjacent each end of the sheet 9, a semi-circular member .150 (Fig. 7) having a groove 151 in its upper edge through which the tape slides. The sides of the groove incline inwardly a slight amount to hold the tape for angular movement with the member 151). The curved portion of the member rests in a semi-circular recess 152 formed in a stationary side plate 153. Formed on one side of the member 150 is a flange 154 engaging the plate 153, and fixed, as by brazing, to the member 159 at the opposite side of the plate 153, is a yoke 156. A pin 157 threadedly engages the yoke and extends through an arcuate slot 158 in the plate 153 to hold the member 150 in the recess 152 and to permit its angular movement. Mounted on the member 150 is a pin 160 extending through a forked portion 161 of a lever 162 pivotally mounted on the plate 153 and carrying a roller 163 engaging a cam 164 on a shaft 165 which is rotatably supported by side plates, not shown. A single rotation of the cam causes the member 150 to be rocked first to a position holding the tape vertical with the written information facing the sheet 9 and then back to its horizontal position. The Eats 15 and 16 are slidably mounted on horizontal shafts 166 and may be moved toward each other for pressing the tape against the sheet 9. Mounted within the bar 16 is an electrical heating element 168 which heats the paper and the ink powder to cause the latter to affix itself to the paper.

For moving the bars 15, 16 on the shafts 166, there are provided levers 169 and 170 (Figs. 1 and 8) pivotally connected at one end to the bars and pivotally connected at points between their ends to a stationary support. Pivotally connected to the levers at their lower ends are links 172;, 173 which extend toward each other and are pivotally connected at their inner ends to a common follower 174 engaging a cam 175 on the shaft 165. Rotation of the cam 175 causes the links to be actuated so as to effect a swinging of the levers 169, 170 in a direction to move the bars toward each other. A spring 176 is connected between the lower ends of the levers for swinging the latter in a direction to move the bars apart as the low dwell of the cam engages the follower 174.

Rotation of the shaft 165 is effected by a belt 177 engaging a pulley 178 on the shaft 26 and a pulley 179 freely mounted on the shaft 165. A clutch for connecting the pulley 179 to the shaft 165 may comprise a helical spring 180 surrounding one end of the shaft 165 and a hub portion on the pulley 179. The spring flexes, when released, into engagement with the shaft and the hub portion for connecting them together. Fixed to one end of the spring is a clutch element 181 loosely mounted on the hub portion and having a shoulder engageable by an arm 182.. Another clutch element 184 is connected to the opposite end of the clutch spring and is aflixed to the shaft 165. Formed on the element 184 is a shoulder which is engageable by a spring urged dog 185, as shown. The arm 182 is moved out of engagement with the element 181 by the pulsing of a magnet 186, and the clutch spring then connects the pulley to the shaft for driving the latter. At the end of one revolution, the arm 182 engages the element 181 to hold one end of the spring. The shaft 165 turns some due to inertia and causes the element 184 to turn to a position so the dog engages its shoulder. The spring is then in an expanded condition free of the shaft and is held this way by the arm 182 and the dog 185.

Pulsing of the print clutch magnet is accomplished by actuating the print key 14 to transfer contacts 188 (Figs. 1 and 9) and connect a condenser 189 between the positive and negative sides of a voltage source for charging it. When the print key is released, the condenser 189 is connected by the contacts 188 (normally closed) across the print clutch magnet 186 to energize the latter and lift the arm 182. The cams 164 and 175 are then driven to tilt the tape and to move the bars 15, 16 toward each other. As the lever 170 is rocked to move the bar 15, it closes contacts 190 (Fig. 1) which operate, as shown in Fig. 10, to short circuit a resistor 191 connected in series with the heater element 168 across a current transformer 192. With the resistor 191 cutout, the element 168 heats quickly to cause the ink powder to adhere to the paper.

If desired, the print clutch magnet may be pulsed automatically as soon as the tape is moved by the tabulating mechanism to a position for printing. This is accomplished, as shown in Figs. 1 and 9, by connecting relay transfer contacts R3c in the circuit between the condenser 189 and the print key 14. The normally closed side of these contacts connect the condenser to the print key, and the normally open side of the contacts connect the condenser 189 through an automatic print switch 194 to the positive side of the voltage supply. Assuming that the switch 194 is closed, the relay contacts R3c transfer as soon as the tab key 12 is depressed and connect the condenser 189 across the voltage source so it becomes charged. When the tab operation is completed, the contacts R30 return to their normal position and connect the condenser 189 across the magnet 186, thereby energizing the latter to cause printing.

As soon as a line of information on the tape has been printed, the keys 1 may be actuated to write another line. The portion of the tape from which printing has been obtained eventually passes the erase head 22 which may be continually energized from an AC. source 195 on closing a manually operated switch 196. The tape is demagnetized by the erase head so that any ink remaining after a print operation is released. The brushes 23 then remove any loose particles of ink before the tape is moved again past the write head.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore, to be limited only an indicated by the scope of the following claims.

What is claimed is:

1. A typewriter comprising, in combination, a member carrying elements made of a magnetic material and shaped at one end in the form of characters to be printed, a magnetic tape movable in a path closely adjacent said one end of said elements, a magnetic head having pole pieces arranged so that flux produced on the pulsing of said head passes between said pole pieces through one of said elements and said tape, thereby magnetizing said tape in the shape of the character on the element through which the flux passes, means for driving said member so as to move said elements serially between said pole pieces, key levers representative of characters to be printed, means operating on the actuation of any one of said key levers for pulsing said head when the one of said elements bearing the character corresponding to key actuated comes between said pole pieces, means operating after each pulsing of said head for advancing said tape one character space, a device for applying powdered magnetic ink to said tape for developing characters thereon, means including a space bar operable to advance said tape one word space, and means operable after a line of information has been written on said tape for pressing the latter against a sheet of paper to effect printing.

2. The typewriter or claim 1 in which said member carrying elements is in the form of a wheel comprising a pair of discs spaced axially a short distance from each other, aligned openings in said discs adjacent their peripheries for receiving said elements, the inner ends of said elements being formed in the shape of a character to be printed, one shaped in the true form of the character and the opposite element shaped in the mirror image form, and said tape being movable between the inner ends of said elements.

3. The typewriter of claim 1 in which said tape lies in a horizontal plane and moves transversely of the typewriter, said elements having characters formed thereon in such a manner that characters written magnetically on the tape are inverted with respect to the operator, and a mirror arranged above said tape for reflecting characters from the tape to the operator in true form.

4. The typewriter of claim 3 in which said mirror is so arranged that it not only reflects information from said tape to the operator but also permits the operator to see the reflected information against a sheet of paper in the position at which printing of the information will take place.

5. The typewriter of claim 3 in which said mirror not only reflects information from said tape to the operator but also permits the operator to look through it for reading information on a sheet of paper, the arrangement of said mirror being such that the reflected information may be seen against the paper in a position in which it will be printed from said tape, thereby permitting the operator to determine if printing will take place in the proper position relative to information al ready printed.

6. A typewriter comprising, in combination, key lever's representative of characters to be printed, a magnetic tape lying in a horizontal plane and movable transversely of said. key levers, a type wheel carrying elements made of a magnetic material and shaped at one end in the form of said characters, means for rotating said type wheel so the character ends of said elements move in a path closely adjacent one side of said tape, a magnetic head having pole pieces arranged so that flux produced on the pulsing of said head passes between said pole pieces through one of said elements and said tape, thereby magnetizing said tape in the shape of the character on the element through which the flux passes, said elements moving serially between said pole pieces during rotation of said Wheel, means operating on the actuation of any one of said key levers for pulsing said head when the one of said elements bearing the character corresponding to the key actuated comes between said pole pieces, means operating after each pulsing of said head for advancing said tape one character space, means including a space bar operable to advance said tape one word space, a device for applying a metered quantity of powdered magnetic ink to said tape after each advance of the latter for developing characters thereon, a pair of pressure bars extending longitudinally of said tape adjacent its opposite edges, means for supporting a sheet of paper between the rear edge of said tape and the pressure bar adjacent thereto, a print key, and means operable on actuation of said print key for turning the section of said tape on which information is written to a vertical position with the characters developed thereon facing said sheet of paper and then moving said pressure bars to press said tape section against said sheet of paper for eiiecting printing.

7. The typewriter of claim 6 including a heating element in one of said pressure bars for heating the latter to cause an affixing of said powdered ink to said paper.

3. The typewriter of claim 6 in which said elements lie adjacent the periphery of said type Wheel with the elements around one half the periphery bearing lower case characters and those around the other half bearing upper case characters, a shift key movable from a normal to a shift position, means operating on actuation of any one of said key levers while said shift key is in normal position for pulsing said head when the one of said elements bearing the lower case character corresponding to the key lever actuated comes between said pole pieces, and means operating on actuation of any one of said key levers while said shift key is in its shift position for pulsing said head when the one of said elements bearing the upper case character corresponding to the key lever actuated comes between said pole pieces.

9. The typewriter of claim 6 including a tab key, and means operating on actuation of said tab key for advancing said tape until the first character developed thereon is located a predetermined distance from one edge of said paper.

10. The typewriter of claim 6 including means operating automatically on Writing a line of information of predetermined length on said tape for advancing the latter until the first character Written is located a predetermined distance from one edge of said paper.

11. A typewriter comprising, in combination, key levers representative of characters to be printed, an endless magnetic tape, means supporting said tape for circulation in a vertical plane extending transversely of said key levers, a type wheel carrying elements made of a magnetic material and shaped at one end in the form of said characters, means for rotating said type wheel so the character ends of said elements move in a path closely adjacent one side of said tape, a magnetic head having pole pieces arranged so that flux produced on the pulsing of said head passes between said pole pieces through one of said elements and said tape, thereby magnetizing said tape in the shape of the character on the element through which the flux passes, said elements having characters formed thereon in such manner that information written on the tape is inverted with respect to the operator, means operating on actuation of any one of said key levers for pulsing said head when the one of said elements bearing a character corresponding to the key actuated comes between said pole pieces, means operating after each pulsing of said head for advancing said tape one character space, means including a space bar operable to advance said tape one unit space, a device for applying a metered quantity of powdered magnetic ink to said tape after each advance of the latter for developing characters thereon, a mirror arranged above said tape for reflecting characters from the tape to the operator in true form, means for supporting a sheet of paper at the edge of said tape remote from said key levers, a print key, means operating on actuation of said print key for turning the section of tape on which information is written to a vertical position with the characters developed thereon facing said sheet of paper and then pressing said tape section against said sheet of paper for elfecting printing, and means including an erase head past which said tape moves after printing takes place for erasing information magnetically recorded thereon.

12. The typewriter of claim 11 including by-pass elements carried by said type wheel and made of a magnetic material, said by-pass elements varying in cross sectional area inversely in proportion to the areas of the characters to be printed and movable between said pole pieces simultaneously with said character bearing elements for bypassing a varying portion of flux.

13. The typewriter of claim 11 in which each of said keys levers is operable for writing either a lower case or an upper case character, said type wheel carrying a separate element for each of said lower and upper case characters, said elements for said lower case characters being arranged around one half of said type wheel and said elements for said upper case characters being arranged around the opposite half of said type wheel, a shift key, means operating when said shift key is in its normal position for pulsing said head when an element bearing a lower case character corresponding to an actuated key lever comes between said pole pieces, and means operating when said shift key is in a depressed position for pulsing said head when an element bearing an upper case character corresponding to an actuated key lever comes between said pole pieces.

14. A typewriter comprising, in combination, key levers, each operable to write either a lower or an upper case character, a type wheel having elements of magnetic material arranged around its periphery, each of said elements being shaped at one end in the form of either a lower case or an upper case character, a magnetic tape movable in a path closely adjacent the character ends of said elements, a magnetic head having pole pieces arranged so that fiux produced on the pulsing of said head passes between said pole pieces through one of said elements and said tape, thereby magnetizing said tape in the shape of the character on the element through which the flux passes, means for rotating said type wheel so as to move said elements serially between said pole pieces, said elements arranged on said type wheel so that those bearing lower case characters extend around one half the periphery of said type wheel while those bearing upper case characters extend around the other half, a circuit for energizing said head,.said circuit including normally open contacts, a member carrying a plurality of contacts equal to half the number of said elements, a contact arm connected at one end to one of said open contacts and engagcable at its other end with said plurality of contacts, means for rotating said arm so it engages one of said plurality of contacts each time one of said elements comes between said pole pieces, means 13 for applying a voltage to a selected one of said plurality of contacts on actuation of a selected one of said key levers, a shift key, means operating on actuation of said key levers for closing said normally open contacts during periods while said elements bearing either lower or upper case characters pass said head, the period of closing depending on the position of said shift key, said circuit energizing said head when said normally open contacts are closed and said contact arm engages the one of said plurality of contacts corresponding to an actuated key 10 lever, means for advancing said tape after said head has been energized, a device for applying powdered magnetic ink to said tape for developing characters written thereon, and means for pressing said tape, after characters have been developed, against a sheet of paper for efiecting printing.

References Cited in the file of this patent UNITED STATES PATENTS 2,841,461 Gleason July 1, 1958 FOREIGN PATENTS 734,909 Britain Aug. 10, 1955 OTHER REFERENCES General Electric Review, July 1952, 346, 74 MP (pgs. 20, 21, 22, 61, photo Copy in 346-74 MP, Div. 16). 

